Stabilized high film strength lubricating oil



STABHJHZEID HKGH WM STRENGTH LUBRHCA'EWG on.

ltubri-Zol Development (Corporation,

Cleveland,

Uhio, a corporation of Delaware No Drawing. Application February 29, 1940, Serial No. 321,480

1 Claim.

Our invention relates to a stabilized high film strength lubricating oil, and more particularly to a composition of matter comprising a hydrocarbon oil of increased film strength obtained by the addition of a chlorinated organic compound, which composition has been stabilized.

This application is a continuation-in-part of our copending application, Serial No. 64,706, filed February 19, 1936, now issued as Patent No. 2,217,173 of October 8, 1940.

It is known that the addition of small quantities of chlorinated organic compounds in general to a hydrocarbon oil will impart thereto an increased iilm strength. As ordinarily prepared, the chlorinated carbon compounds are refined after chlorination by blowing with air to remove excess chlorine and hydrochloric acid. The chloiinated compounds are then given a wash with a solution of a reducing or oxidizing agent to rove labile chlorine. After water washing and drying, the chlorinated compounds are fairly stable witl respect to the development of hydrochloric acid in storage. The degree oi stability is largely dependent on the severity of the oxidizing or reducingtreat given. The severity of this treat in turn is governed'by the amount of treating loss which ensues with said treating. In order to economically refine a chlorinated compound as for exple, a chlorinated ester of a fatty acid, this treating should not be too severe. Therefore, the finished product is never as stable as is desired especially if it is to be stored in iron containers during the warm months of the year. "at 11... a is true of the chloro-ester is true broadly for all chlorinated organic compounds in general. We find that chlorinated compounds and esters in particular, stored under these conditions, quite often develop hydrochloric acid in a low weeks time. When this occurs the product t 1.. 2-: dark and some of the esters hydrolize, thereby lncreasingthe free fatty acid. This is obviously oblectlonabl When samples of the ordinarily prepared and refined chloro-esters are exposed to sunlight, either directly or indirectly, for a few days in glass containers, some hydrochloric acid develops and tends to cause hydrolysis. This is analogous to the development of hydrochloric acid in the darlr in iron containers d the warm months. ll; test was developed to correlate the stability of gthechloro-esters in sunlight and the stability in iron) containers.

Standard one-pound grease c were cleaned and 25 cc. of the chloro-esters to be tested were poured into them. lhe cans at=2 tju F. until they developed were then held hydrochloric acid and turned dark. It was found that 1 /2 hours without change at 240 F. in this test was equivalent to about three weeks exposure to indirect sunlight.

We have found that a number of compounds, when added to halogenated organic compounds in small amounts, greatly increased the period of time which was required to induce the formation of hydrochloric acid under the conditions of these two tests. The compounds which had the greatest effect were the terpene hydrocarbons. In particular, pinene was found to be an extremely potent stabilizer. For example, the straight methyl chloro stearate developed a strong odor of hydrochloric acid in less than a month's time. A blend of one per cent of pinene in the same chloro-ester did not develop a trace of hydrochloric acid after a years exposure. The length of time before which hydrochloric acid developed in the iron can test at 240 F. described above, was increased by 900 per cent by the addition of one per cent of pinene.

Other terpene hydrocarbons which can be employed are myrcene, ocimene, limonene, hemiterpenes, di-terpenes, poly-terpenes, and the like. Terpene derivatives are also of value although they; are not as efiective as the hydrocarbons. Examples of these are geraniol, citronellol, clneol, cal-vine, citrol, and the like.

A second class of compounds which we have discovered very efiective as stabilizers for halogenated compounds was the hydrogenated'derivatives of naphthalene, di-, tetra-, hexa-, octo-, and deca-hydronaphthalene. For example, one per cent of tetra-by :tW-hthalene improved the stability of methyl chloro s earate 800 per cent in the test where the samples were exposed to sunlight. 1

A third class of compounds which has considerable stab influence on halogenated compounds are the hydroxy aromatic compounds. One per cent of phenol, para-cresol, naphthol, and para-hydroxy diphenyl each increased the stability of the chloro esters by 500 to 900 per cent. Derivatives of the phenols are also operative. Oneper cent of ortho nitro phenol increased the stability of methyl chloro stearate by 800 per cent.

While a number of other compounds have some stabilizing influence on chloro-esters, the above three groups are outstanding. Three compounds not included in these groups, which have considerable merit, are cholesterol, ethyl abietate, and acetal.

Ethyl abietate is representative of a class oi alicyclic compounds which are in fact cyclic but have many properties of the" aliphatic compounds or properties which make them resemble the aliphatic compounds. Alicyclic compounds having a. vapor pressure greater than atmospheric at a temperature above about 200 F. are as a class usable in our invention.

Some of these alicyclic compounds are hydrocarbons while others' are alcohols, aldehydes, ketones, acids, esters,-ethers, etc., both chemically .with some good effects.

saturated and unsaturated. Some of the cyclo-- propane derivatives are satisfactory for use in our invention while others have a boiling point below 200 F. Cyclo butane is not sufiiciently high boiling but most of its derivatives are satisfactory. For example cyclobutanol, cyclobutylcarbinol, cyclobutanone, cyclobutyl methyl ketone. cyclo butane,'monocarboxylic acid, etc., are all satisfactory. Other alicyclic compounds which may be used in our invention include those cycloaliphatic compounds with five, six, seven, or more carbon atoms in the ring and their derivatives. Methylcyclopentanone, sylvestrene, quinitol, inositol, cyclohexanone, carvone, thujane, sabnene, sabinol, etc., are other alicyclic compounds that may be used in our invention.

Compounds which react with hydrochloric acid easily and hold the halogen acid firmly have been found to be of advantage in practicingour invention. Some of the other halogenated organic compounds which have been stabilized by the previously mentioned stabilizing agents are:

Halogenated aliphatic hydrocarbons such as halogenated wax and halogenated petroleum oils; halogenated aromatic hydrocarbons such as halogenated benzene, naphthylene, diphenyl, anthracene, and the like; halogenated aliphatic, aromatic, and hetero cyclic alcohols, aldehydes, ke-

tones, acids, esters, ethers, etc.; mixtures of various halogenated organic compounds with each other and with amines, nitro compounds, phosphorus-containing compounds, thio compounds, etc. a

In practicing this invention, quantities of the stabilizer of as small as .01 per cent of the chicrinated-carbon compound content may be used The more of the stabilizer used with the chloro-ester, the more stable the resulting blend will be,however, the nearmaximuin effect is obtained with one per cent or less. For example, .l-per cent of pinene increased the stability in the iron can test 100 per cent, while .25 per cent increased the stability 500 per cent and one per cent increased the stability only 900 per cent.

' For each stabilizer there is a percentage which is most effective in improving the stability most economically. The stabilizer may be incorporated into the halogenated organic compound at-,any

period during its manufacture after air blowing (following chlorination) to remove excess ch1o-.

rine. vIt is preferable, however, to add it immediately after the final drying process.

The stabilizers described in this invention not only act efiectively in stabilizing organic chlorine compounds in general, and especially chloroesters of fatty acids, but also'reduces the corrosiveness of blends of halogenated organic compounds in. lubricating oil. For example, a blend of one per cent of fairly stable methyl chlorostearate in oil caused a loss of 20 mg. per 100 sq. cm. of bearing metal in a corrosion test conducted at 300 F. for forty-eight hours. A blend of one per cent of the same ester stabilized with one per:cent of pinene ,in oil in the sametest caused aloss of 8 mg. per 100 sq. cm. of the same bearing material. Therefore, the stabilizer in the chloro ester gives a lubricating oil blend of improved stability.

Having thus described our invention, we claim:

A composition of matter comprising in combination a major portion of a lubricant, from .5 percent to 10 percent by weight of a chlorinated carbon compound and from .001 percent to 1 percent by weight of ethyl abietate.

BERT H. LINCOLN. WALDO L. STEINER. 

